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Entanglement of Thread Molecules and Its Influence on the Properties of Polymers
Author(s) -
Hoffmann Martin
Publication year - 1977
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.197707511
Subject(s) - quantum entanglement , polymer , macromolecule , viscosity , molecule , chemical physics , relaxation (psychology) , thermodynamics , chemistry , materials science , physics , quantum mechanics , quantum , psychology , social psychology , biochemistry , organic chemistry
This article shows the extent to which the entanglement of threadlike molecules can influence many of the properties of deformable polymers and of solutions of macromolecular substances. Thus, the molecular concept of entanglement leads to quantitative predictions of the dependence of the entanglement number on the nature of the polymer, its concentration, and extension. Experimental values of the relaxation modulus confirm these predictions for melts and solutions. The influence of entanglemnt on relaxation and flow processes leads to very simple relationships for the magnitudes of the structural viscosity and the shear stress at which the structural viscosity starts to become measurable. Osmotic pressures, light scattering intensities, and diffusion coefficients of concentrated solutions can be derived quantitatively from the conformational constraints due to entanglement. Entanglement is effective above a concentration at which the three‐dimensional coils fill the solution volume, and probably also at lower concentrations. At very high concentrations entangled structures may be formed which drastically reduce the number of possible conformations. The swelling and extension behavior of cross‐linked deformable polymers can be understood only if entanglement is taken into account.